topic BDM connection problem MC9S12C32 in S12 / MagniV Microcontrollers

BDM connection problem MC9S12C32

Shugie — Fri, 12 Oct 2007 04:41:57 GMT

I am using hiwave debugger with PE micro's BDM_multilink and the C32. I have just built a board and am trying to put code on my chip. When I connect the BDM to the board, the yellow light (signaling a connection) flashes on only briefly. Hiwave then seems to want to let me do anything, however I keep getting an error that looks like "BDM register not set, hardware reset may have occured". The physical reset line does not go low when I check it. What could be causing this?

Re: BDM connection problem MC9S12C32

jsmcortina — Fri, 12 Oct 2007 04:52:39 GMT

I'm using the S12C64 with Codewarrior and HIWAVE.

I don't know why but the S12 BDM programmer is utter junk compared to the S08 version.

The S08 one is rock solid, simple to use and works great.

I usually get problems when using the S12 version. Check your variant is set correctly, mess with the register and clock settings, unplug the USB cable etc.

James

Re: BDM connection problem MC9S12C32

Alban — Fri, 12 Oct 2007 05:09:02 GMT

Hello,

Difficult to be totally affirmative because of the level of details.

Add a pull-up resistor of 5-10k Ohm between BGND and VDD pins on the BDM connector of your board.
This particularly more important on higher speed crystal with longer PCB tracks (added capacitance) to allow the background line to get back to Vdd fast enough when not driven.

If this does not work, please come back with more details.
If this does, please also tell us to help other users.

Before TBDML, I was using USBMULTILINK on S12(X) daily without trouble.

Alban.

Re: BDM connection problem MC9S12C32

Shugie — Fri, 26 Oct 2007 01:15:46 GMT

Thank you for the quick reply. We have a 47k pullup resistor attached. Is that too much? It has worked on other boards in the past. To provide some more details: we just designed a new PCB that uses the micro to control a few sensors. After it is all soldered up I try to connect the BDM and just get a quick yellow light on the pod. I have seen this 1 time before when a chip was blown, but it has happened on 2 chips now and I think maybe I did something wrong. I used the bypass capacitors suggested in the manual, a 8 Mhz crystal oscillator, and a pll circuit consistent the the s12_pll_filter_calculator.exe program I downloaded. When I scope various pins on the C32 I see that the PLL pins are giving 2.5V (in spec) and the Oscillator is working which means the C32 has power and is redistributing it. However, if I can't connect the BDM I don't know anything else.